Lightweight honing tool and hone strip

ABSTRACT

The present invention relates to a honing tool having a tool body in lightweight construction, and at least two radially feedable hone strips, the hone strips being radially feedable via a rack-and-pinion gear, the rack-and-pinion gear comprising a central toothed shaft adapted and arranged to interact with racks associated to the respective hone strips to feed the hone strips, wherein the honing tool comprises a pneumatic measuring device for in-process diameter measurement of a diameter of an opening to be machined in a workpiece.

The present invention relates to a honing tool for honing the inner surface of an opening in a workpiece, wherein the honing tool is designed according to the preamble of claim 1. The invention also relates to a hone strip having honing stones.

During honing, the respective honing tool is inserted into the opening to be machined. For this purpose, the honing tool can be moved into the stationary opening or the workpiece with the opening can be moved relative to the stationary honing tool such that the honing tool is inserted. Subsequently, the movement of a rotation in circumferential direction with superimposed up and down movement of the honing tool in axial direction within the opening is carried out, which is typical for hone machining. Also in this case, the workpiece or the honing tool or both can be moved so that the corresponding relative movement between workpiece and honing tool is present.

Conventional honing tools have a tool body that is solid, i.e. that has a one-piece base body, whereby this base body is usually made of a solid material. Usually the hone strips or honing stones and an infeed device usually in the form of an infeed cone attached to an infeed rod are arranged within the base body. Furthermore, lightweight honing tools are known which do not have a tool body with a solid base body, but a multi-piece tool body. With this lightweight construction, the tool body usually has plate-like elements extending orthogonally to the axial direction. Along the axial direction, usually elongated elements are provided which are bar-shaped or extend in a different manner in the axial direction and are connecting the plate-like elements. Such lightweight honing tools can be manufactured at low costs, however, in use only less precise results can be obtained than with conventional honing tools. Due to the lightweight construction, such tools are more susceptible to vibrations and oscillations during machining. When using lightweight honing tools, the machining of the opening is usually controlled by a timing or by a drop measuring sleeve.

It is the object of the present invention to provide a honing tool which can be manufactured with low costs and enables surface machining of the inner walls of an opening with improved accuracy. According to the invention, this object is achieved by a honing tool according to claim 1.

Another object is to provide a honing strip where honing stones can be easily replaced. According to the invention, this problem is solved by a hone strip according to claim 9. With conventional honing tools in lightweight construction, the honing stones are adhered onto the hone strips or attached to them in some other undetachable way. The replacement of the honing stones, when they are worn out by the machining, is complex, which has a negative effect on the operating costs. The honing tool according to the invention is of lightweight construction and therefore does not have a tool body with a solid base body, i.e. a base body made of one piece, but the tool body of the honing tool according to the invention comprises a cage-like structure of individual interconnected elements. The honing tool also comprises at least two hone strips configured for radial infeed. The term radial infeed means that the hone strips can be variably positioned in a radial direction orthogonal to the axial direction. The axial direction corresponds to the direction in which the honing tool is moved up and down. Preferably, the hone strips of the honing tool are arranged on the tool body evenly distributed in the circumferential direction. The individual hone strips can each carry one or more honing stones. With the honing tool according to the invention, the radial feedability of the hone strips is implemented by a rack-and-pinion gear. The hone strips are assigned to the respective gear racks. A hone strip can be feedable by means of a single toothed rack. It is, however, also within the spirit of the invention if each hone strip comprises at least two racks preferably arranged at a front end and a rear end, in axial direction, of the hone strips. However, other rack arrangements which permit radial infeed are also conceivable and within the spirit of the invention. These racks interact with a central toothed shaft to form the gearbox. By rotation of the toothed shafts, the racks can be moved and by this movement, the hone strips can be adjusted in their radial position.

In other words, the rotational movement of the rack relative to the tool body is converted by the rack gear into a translational movement of the racks relative to the tool body, allowing the hone strips to be moved translationally in a radial direction.

According to the invention, the honing tool comprises a pneumatic measuring device for in-process diameter measurement of a diameter of the opening to be machined in the workpiece. By means of this pneumatic measuring device, which can determine the diameter of the bore to be machined with high accuracy on the basis of a measured pressure, it is possible to precisely determine the progress of the honing process.

The tool body of the honing tool can be dividable into a functional section and a coupling section. The functional section supports the components relevant for honing, such as the hone strips and the pneumatic measuring device. The functional section and the coupling section can, for example, be formed by components that can be separated from each other. However, they can also be formed by the same components while the distinction is functional in nature, so that the honing operation is performed by the functional section and the coupling section forms an interface for coupling to a honing spindle. In particular, the coupling section may comprise an interface for coupling the honing tool to a honing spindle, e.g. in the form of a coupling flange. It can be advantageous if the functional section is gimbal-mounted relative to the coupling section. In particular, it is possible for the honing tool to virtually center itself in the opening to be machined, resulting in a particularly uniform surface finish. For example, the coupling section may comprise a flange that can be attached to a corresponding counter flange on the honing spindle. The toothed shaft of the rack-and-pinion gear typically extends through such a coupling flange. If the functional section is gimbal-mounted relative to the coupling section, the rack can additionally be connected via a cardan joint, by means of which the toothed shaft can be connected to an appropriate drive for the infeed of the hone strips on the side of the honing spindle.

The coupling flange of the coupling section can, for example, be constructed with a coupling plate on the spindle side. It is possible that extensions, in particular two extensions, extend from the coupling plate on the spindle side in axial direction into the functional section. Such extensions, especially if there are two extensions, can form a bearing fork for the gimbal bearing of the functional section relative to the coupling section. For the implementing the gimbal bearing it can be intended that a first pivoting element is mounted pivotable about a first pivoting axis relative to the two extensions. Such a first pivoting element can be formed by a frame element, for example. Such a frame element can, in turn, be pivotable and arranged between or around the two extensions. A second pivoting element can be arranged opposite the first pivoting element so that it can pivot about a second pivoting axis. The second pivoting axis is orthogonal to the first pivoting axis. The second pivoting element can be pin-shaped and can extend through the frame element. In particular, it may be intended that the second pivoting element is formed as a hollow pin in whose inner cavity, which is oriented in the axial direction, the toothed shaft extends. In other words, the toothed shaft can be enclosed by the second pivoting element.

It may be intended that the functional section comprises two plate-like elements. These plate-like elements can be connected by struts extending in axial direction. It may also be intended that the hone strips and/or the pneumatic measuring device and/or the rack-and-pinion gear are arranged entirely between the plate-like elements. The plate-like elements can form, in axial direction, a front and rear boundary of the functional section of the honing tool. The pneumatic measuring device can comprise measuring strips with measuring nozzles arranged thereon. A measuring strip can comprise one or more measuring nozzles. The measuring strips may be held in measuring strip holders, which, in turn, may extend at the above plate-like elements from a first of these plate-like elements to a second plate-like element. It is also conceivable that the hone strips extend from the first plate-like element to the second plate-like element. The extension of the hone strips or measuring strips is typically oriented in axial direction. In other words, it extends in an axial direction.

The pneumatic measuring device can comprise measuring strips which are held in measuring strip holders and on which measuring nozzles are arranged, wherein the radial position of the respective measuring strips can be adjustable in relation to the measuring strip holders. To this purpose, a positioning device is typically provided, which is configured to adjust the radial position of the measuring strips. This allows the honing tool to be easily adapted for machining different nominal diameters.

Such a positioning device can be implemented, for example, by a screw-based mounting of the measuring strips in relation to the measuring strip holder or of the measuring strip holder in relation to the functional section or its frame structure, in particular in relation to the plate-like elements of the frame structure.

The positioning device may be formed by a screw-based mounting of the measuring strips in relation to the functional section. In particular, the mounting of the measuring strips can comprise at least one first screw which is screwed into the functional section 12 and holds the measuring strip or the corresponding measuring strip holder from the radial outside. Furthermore, the positioning device may comprise a second screw which is screwed into the measuring strip or the corresponding measuring strip holder and abuts on the functional section such that the measuring strip can be moved radially outwards relative to the functional section by screwing the second screw into the measuring strip or the corresponding measuring strip holder. To this, the second screw can bear on the frame structure with its end facing away from the measuring strip, for example, and screwing the second screw into the measuring strip or the measuring strip holder thus causes the measuring strip or the measuring strip holder to be spaced apart from the functional section or its frame structure, in particular in relation to the plate-like element of the frame structure. Typically, the second screw can be formed as a headless threaded bolt.

At both axial ends of the measuring strips or measuring strip holders a respective positioning device may be arranged.

The hone strips and/or measuring strip holders can be detachably mounted to, in particular screwed on, the tool body. Typically, the measuring strips are formed such that the measuring nozzle is arranged, in axial direction, in the center of the measuring strip.

It may be intended that the measuring strip has at one axial end a connection for a pressure medium supply. This connection can lead into a pressure media channel extending in axial direction through the material of the measuring strip. The pressure media channel, which can extend through the material of the measuring strip, can directly lead into the measuring nozzle. Typically, the connection for the pressure medium is located at the spindle side end of the measuring strip.

It is also conceivable that a tube-like extension is attached to measuring strip holders and forms a supply for a pressure medium to the measuring nozzle. Typically, such a tube-like extension coming in axial direction from the honing spindle firstly extends in the axial direction and then has a bend so that it extends in the radial direction, and then leads into the measuring strip holders. The tubular extension can protrude into the material of the measuring strip holders.

A honing tool of one of the types described in this application is also a part of the invention, whereby the hone strips of the honing tool are formed according to one of the general types described in the following in connection with the figures and the claims.

A hone strip is also part of the present invention, in particular for use in an above described honing tool, with a support and at least one honing stone. In accordance with the invention, the support has a clamping device by means of which the at least one honing stone can be releasably clamped and fixed to the support in a clamping position of the clamping device. Such construction allows a reliable attachment of at least one honing stone to the support and at the same time a simple replacement of worn honing stones. For replacing a honing stone, only the clamping device has to be released without, for example, the need of separating adhesive or solder joints in an laborious way. This considerably facilitates the maintenance of a honing tool, thereby reducing non-productive times and thus operating costs. The support can be designed such that, when looking radially at the hone strip, it projects beyond the honing stone or honing stones in the circumferential direction and/or in the axial direction. The support can be virtually formed such that it forms a kind of frame for the honing stones, or in other words, that it surrounds the honing stones like a frame.

The clamping device may comprise at least one joining section and one clamping element. In particular, the joining section is fixedly arranged on the support. It is conceivable, for example, that the joining section is formed in one piece with the support. The joining section can be formed such that the at least one honing stone in the clamping position abuts on the joining section in the circumferential direction. In the clamping position, the clamping element can be arranged circumferentially on the opposite side of the honing stone, abut on it and urge it circumferentially against the joining section so that the honing stone is clamped and held between the joining section and the clamping element. It is particularly preferred that a contact between the joining section and the honing stone and/or a contact between the clamping element and the honing stone is possible along the entire axial extent of the honing stone. This enables secure fixation of the at least one honing stone to the support. In particular, slipping of the honing stone during machining of a workpiece is prevented, which is advantageous for high machining accuracy.

The clamping device may comprise a fixing element which is designed and arranged such that in the clamping position it abuts on the clamping element and urges the same towards the joining section. This makes it possible to provide a clamping effect to the at least one honing stone by applying a force to the fixing element. The fixing element can also be used for releasably fixing the clamping element to the support. It is conceivable, for example, that the fixing element is designed and arranged such that in the clamping position it additionally urges the clamping element towards the support, so that the clamping element is clamped and held between the fixing element and the support.

A contact surface between the joining section and the honing stone may be located in a plane which extends substantially in the axial and radial directions. It is also conceivable that a contact surface between the clamping element and honing stone lies in a plane that extends substantially in the axial and radial directions. Such configuration is advantageous in that the at least one honing stone, considered in a circumferential direction, is held between the joining section and the clamping element by form-fit. In this way, the forces transmitted to the honing stone in the circumferential direction during machining (e.g. frictional forces between honing stone and workpiece due to the rotary movement of the honing tool) can be safely transferred to the support. Slipping of the honing stone can thus be prevented, which contributes to a high precision during machining.

A contact surface between the fixing element and the clamping element may be located in a plane which extends in the axial direction and extends in a further direction which has an angle relative to the radial direction when looking at a plane extending orthogonally to the axial direction, wherein this angle is between 15° and 45°, in particular between 20° and 40°, in particular between 25° and 35°. This makes it possible to transfer a movement of the fixing element in the radial direction into movement of the clamping element in a circumferential direction (gear function).

The clamping element and the fixing element may be formed and arranged such that the fixing element urges the clamping element in the circumferential direction towards the honing stone when the fixing element moves in a radial direction, in particular radially inwards. A movement direction of the fixing element and a movement direction of the clamping element are therefore decoupled. This makes it possible to exert a clamping force on the at least one honing stone in the circumferential direction by applying a force to the fixing element in the radial direction.

The clamping device may also include a tensioning mechanism configured to move the fixing element, when transferring it into the clamping position, in a radial direction, in particular radially inwards. When the fixing element moves radially inwards, the at least one clamping element is preferably urged in the circumferential direction towards the honing stone, so that, in turn, the latter is urged towards the joining section. This makes it possible to exert a clamping effect on at least one honing stone via the clamping mechanism. The tensioning mechanism can also be used to secure the fixing element and/or the clamping element against loss.

The tensioning mechanism can, for example, be a screwed connection. It is possible, for example, that the fixing element can be detachably fastened to the support by means of one or more fastening screws and that when the at least one fastening screw is tightened, the fixing element is moved in the radial direction, in particular radially inwards. This ensures a particularly simple and reliable clamping of the at least one honing stone to the support. A configuration of the clamping mechanism as a screwed connection also has the advantage that a worn honing stone can be replaced particularly easily and with merely minor usage of tools. Merely the at least one fastening screw must be released, e.g. by means of a screwdriver, in order to remove a clamping effect of the clamping device.

According to a preferred embodiment, the hone strip may comprise two honing stones. In this case, the clamping device may comprise two circumferentially outer joining sections, two clamping elements arranged between the honing stones when viewed in the circumferential direction, and at least one fixing element arranged between the clamping elements when viewed in the circumferential direction.

Preferably the honing stones in the clamping position abut on one of the two outer joining sections. In the clamping position, the clamping elements preferably abut on a honing stone. The fixing element may preferably have a trapezoidal cross-section, in particular in the form of a symmetrical trapezium. Preferably, the two non-parallel leg surfaces of the trapezium form the contact surfaces to the clamping elements. This enables to strain both clamping elements simultaneously—in opposite directions—in the circumferential direction by straining one fixing element. This has the advantage that a clamping force of the same amount can be applied to both honing stones. Furthermore, in this way, a particularly quick and easy replacement of the two honing stones can be achieved, since merely one fixing element needs to be released to remove the clamping effect.

Further features, possibilities of application and advantages of the invention can be derived from the following description of embodiments of the invention, which are explained with reference to the drawings, wherein the features can be essential to the invention when considered singly or in various combinations, even if not explicitly pointed out again. The figures are showing:

FIG. 1 a perspective view of a honing tool according to the invention;

FIG. 2A a side view of the honing tool of FIG. 1;

FIG. 2B a view when looking onto an end of the honing tool facing away from the spindle of FIG. 1;

FIG. 3A a sectional view of the honing tool along the section planes IIIa-IIIa;

FIG. 3B a sectional view of the honing tool along the section planes IIIb-IIIb;

FIG. 4 a sectional view of the honing tool along the section planes IV-IV;

FIG. 5A a sectional view of an alternative measuring strip holder;

FIG. 5B a perspective view of an alternative measuring strip holder;

FIG. 6A a perspective view of the alternative measuring strip or measuring strip holder, respectively, of FIGS. 5A and 5B;

FIG. 6B a top view of the alternative measuring strip or measuring strip holder, respectively, of FIGS. 5A and 5B;

FIG. 6C a sectional view along the section planes VI-VI of the alternative measuring strip or measuring strip holder, respectively, of FIGS. 5A and 5B;

FIG. 7 an enlarged section of a hone strip of FIG. 3A according to the line VII drawn in FIG. 3A;

FIG. 8 the enlarged section of the hone strip of FIG. 7 in an exploded view;

FIG. 9 a perspective view of a hone strip of the honing tool of FIG. 1;

FIG. 10 a side view of the hone strip of FIG. 9; and

FIG. 11A sectional view of the hone strip of FIG. 10 along the section plane XI-XI.

In the following figures, corresponding components and elements have the same reference signs. For the sake of better clarity, not all reference signs are shown in all figures.

FIG. 1 shows a honing tool 10 according to the invention in a perspective view. The honing tool 10 comprises a functional section 12 and a coupling section 14, which together form a tool body 11. Hone strips 16 are arranged on functional section 12, which in turn comprise honing stones 18. Measuring strip holders 20 with measuring strips 22, which in turn comprise measuring nozzles 24, are also arranged on functional section 12. The construction of the measuring strip holders and measuring strips as well as the hone strips will be described in detail later. The measuring strips 22 form a pneumatic measuring device 26 for in-process diameter measurement of a diameter of an opening to be machined.

Coupling section 14 comprises a coupling flange 28, which is formed as a coupling plate 30 on the spindle side. From coupling plate 30 on the spindle side, two extensions 32 extend in an axial direction A into functional section 12. The two extensions 32 form a bearing fork 34 for a gimbal bearing of functional section 12 relative to coupling section 14.

In FIG. 3A (section IIIa-IIIa), the gimbal bearing of functional section 12 is shown in detail. A first pivoting element 36, which is formed as a frame element 36, is mounted pivotably about a first pivoting axis S1 relative to the two extensions 32. Opposite to the first pivoting element, a second pivoting element 38 is arranged and pivotably supported. Second pivoting element 38 is formed in the shape of a pin and encloses a toothed shaft 40, which forms a part of a rack-and-pinion gear 44. Toothed shaft 40 comprises a gimbal bearing section 43 to compensate relative movements between functional section 12 and coupling section 14. In FIG. 2A, a circumferential direction U is depicted with a correspondingly marked arrow.

In FIG. 3B (section IIIb-IIIb) it is illustrated how the toothed shaft 40 interacts with toothed racks 42, which are assigned to the respective hone strips 16. A rotational movement of toothed shaft 40 is converted into a translational movement of racks 42, which in turn are coupled with hone strips 16. Thus, hone strips 16 are radially feedable, i.e. movable in a radial direction R. Each of the hone strips 16 has a respective rack 42 at its axial front and axial rear ends. This reliably ensures a uniform infeed of the hone strips over the length of hone strip 16 (extension in axial direction A) in the radial direction R. Toothed shaft 40 or the section of toothed shaft 40 interacting with gear racks 42 and gear racks 42 together form a rack-and-pinion gear 44.

Rack-and-pinion gear 44 with the section of toothed shaft 40 interacting with racks 42 and racks 42 itself are arranged between a first plate-like element 46 and a second plate-like element 48, when seen in axial direction A. The first plate-like element 46 forms the spindle side end of the functional section and the second plate-like element 48 forms the end of functional section 12 facing away from the spindle.

Hone strips 16 and measuring strip holders 20 each extend from first plate-like element 46 in the axial direction to second plate-like element 48 (see FIGS. 1, 2A and 2B).

Measuring strip holders 20 of the embodiment according to FIGS. 1 to 4 are rigidly arranged on the respective plate-shaped elements 46, 48, i.e. not movable.

FIGS. 5A to 6C show an embodiment in which measuring strip holders 20 and measuring strips 22 can be positioned variably in the radial direction R. This is clearly illustrated in FIGS. 5A and 5B. Measuring strips 22 are arranged on measuring strip holders 20, as shown in FIGS. 5A and 5B, thus, several screws by which measuring strip holders 20 are each fixed to first plate-like element 46 and to second plate-like element 48 form a positioning device 52. Measuring strip holders 20 are each arranged in recesses 50 which are formed in plate-like elements 46, 48 complementary to measuring strip holders 20.

The positioning device comprises a plurality of first screws 54 (two at the respective axial ends of the measuring strip holders 20, respectively), two of which are shown visibly in the sectional view of FIG. 5A. First screws 54 each extend through a threadless opening of measuring strip holders 20 and are screwed into the respective plate-shaped element 46, 48.

First screws 54 abut with their respective heads 55 on measuring strip holders 20, and thus, hold measuring strips 22 from the radial outside. Measuring strip holders 20 are thus held radially outwards such that they cannot be lost in relation to plate-shaped elements 46, 48.

A second screw 56 is screwed into each of measuring strip holders 20 in the region of their axial ends. On the radially inner side, it protrudes from measuring strip holders 20 and abuts on the respective plate-shaped element 46, 48 (FIG. 5) without being screwed into the same. Measuring strip holder 20 is moved radially outwards relative to the respective plate-shaped element 46, 48 by screwing second screws 56 into measuring strip holder 20, since the part of second screws 56 projecting radially inwards from measuring strip holder 20 is always arranged between measuring strip holder 20 and respective plate-shaped elements 46, 48 and determines their distance from each other. With positioning device 52, the position of measuring strip 22 can be adjusted very accurately by actuating (screwing in or screwing out) the respective first and second screws 56.

As shown in FIGS. 4 and 6A to 6C, the respective measuring nozzle 24 has a respective supply line 60 for a pressure medium. In the embodiment of FIG. 4, supply line 60 extends through the material of measuring strip holder 20. Supply line 60 has a first section 62 extending in axial direction A through the material of measuring strip holder 20 and a second section 64 which exits in radial direction R and runs into the material of measuring strip 22 and extends to measuring nozzle 24 or opens into the same.

In the embodiment shown in FIGS. 5A to 6C, a tubular extension 66 is attached to measuring strip holder 20 and forms a supply for a pressure medium to measuring nozzle 24. The tubular extension 66, coming from the honing spindle in axial direction A, extends firstly in the axial direction A and then has a bend 68 so that it extends in the radial direction R. Thereby, an axial section 70 and a curved section 72 are provided. One or both of sections 70, 72 can be made flexible. Curved section 72 leads into measuring strip holders 20. Tubular extension 66 can protrude into the material of measuring strip holders 20, as illustrated here. However, it can also be flanged to the outside. A fluidic connection of tubular extension 66 extends from its end to measuring nozzle 24. The fluidic connection is formed by a radial channel 74 which extends through the material of measuring strip holder 20 and the material of measuring strip 22.

The structure of a hone strip 16 is explained in detail below with reference to FIGS. 7 to 11:

Each hone strip 16 has two honing stones 18, which preferably extend over the entire axial extension of the hone strip 16—from first plate-like element 46 to second plate-like element 48 of honing tool 10 (see FIGS. 1, 2A and 2B). It is possible that each honing stone 18 in axial direction A is formed by a plurality of subsegments (see FIG. 9). In a new (unused) state, honing stones 18 preferably have an substantially rectangular, in particular square cross-section (see FIG. 7).

Hone strip 16 also comprises a support 76 for receiving honing stones 18. Preferably, support 76 extends along the entire axial extension of hone strip 16 (see FIGS. 9 and 10). Support 76 comprises, on a front side 78 facing away from honing tool 10, two joining sections 80 arranged on the outside in a circumferential direction U and limiting the extension of support 76 along the circumferential direction U (see FIGS. 7 and 8). Joining sections 80 are preferably formed to be symmetrical to a central axis 82 of hone strip 16 parallel to the radial direction R. Joining sections 80 each have a joining surface 84 for joining one honing stone 18, respectively. Preferably, the respective joining surface 84 lies in a plane which extends substantially in the axial direction (in FIG. 7 and orthogonal to the drawing plane) and in the radial direction R.

Support 76 also has a receiving region 86 on its front side 78 which is arranged approximately centrally with respect to the extension of support 76 in the circumferential direction U (see FIG. 8). Receiving region 86 has a bottom surface 88 which is oriented substantially orthogonal to the radial direction R.

Support 76 also has two receiving sections 90 on its front side 78 for receiving one honing stone 18, respectively (see FIG. 8). Receiving sections 90 are substantially symmetrical to each other in relation to the center axis 82 of hone strip 16. Receiving sections 90 are arranged, when seen in circumferential direction U, between central receiving region 86 and one of the two external joining sections 80. Receiving sections 90 each have a receiving surface 92 which, when seen in the circumferential direction, is delimited to the outside by joining surface 84 of the respective joining section 80. The respective joining surface 92 is preferably oriented substantially orthogonally to joining surface 84 of the respective joining section 80.

Support 76 is connected via a screwed connection 98 to a mounting body 96 at a rear side 94 facing honing tool 10 (see FIGS. 10 and 11). Mounting body 96 is, in turn, connected at its axial front end and axial rear end to a rack 42 of the rack-and-pinion gear (see above).

Joining sections 80 are part of a clamping device 100, by means of which the two honing stones 18 can be detachably clamped and fixed to support 76 in a clamping position shown in FIG. 7. Clamping device 100 comprises two clamping elements 102, each of which is used to strain a honing stone 18. Each clamping element 102 is thus assigned to a honing stone 18. Clamping elements 102 preferably extend along the entire axial extension of honing stones 18 (see FIG. 9).

Clamping elements 102 each have an substantially trapezoidal cross-section in a section plane orthogonal to the axial direction. Accordingly, clamping elements 102 in their cross-section have two parallel surfaces (long base surface 104 and short base surface 106) and two surfaces oriented inclined with respect to parallel surfaces 104, 106 (first clamping surface 108 and second clamping surface 110, see FIG. 8). First clamping surface 108 is inclined by an angle between 5° and 10° relative to the surface normal of parallel surfaces 104, 106. Preferably, second clamping surface 110 is oriented relative to the surface normal of parallel surfaces 104, 106 inclined by an angle between 25° and 35°.

Clamping device 100 further comprises a fixing element 112 which preferably extends along the entire axial extension of the honing stones 18 (see FIG. 9). Fixing element 112 has, in a sectional plane orthogonal to the axial direction, a cross-section in the form of a symmetrical trapezium with two mutually parallel surfaces (short base surface 114 and long base surface 116) and two leg surfaces 118 inclined relative to parallel surfaces 114, 116. Leg surfaces 118 are preferably inclined relative to the surface normal of parallel surfaces 114, 116 by an angle between 25° and 35°. In particular, the angle between leg surfaces 118 and parallel surfaces 114, 116 of fixing element 112 corresponds to the angle between second clamping surfaces 110 and parallel surfaces 104, 106 of clamping elements 102.

FIG. 7 shows the hone strip in an assembled state with the clamping device in the clamping position. In the clamping position, honing stones 18 abut with a first side surface 120 on receiving surface 92 of the respective receiving section 90, and abut in the circumferential direction U with a second side surface 122 on joining surface 84 of the respective joining section 80. A contact surface 124 between honing stone 18 and joining section 80 extends in the axial direction A (in FIG. 7 orthogonal to the drawing plane) and in radial direction R (in FIG. 7 for the sake of clarity only exemplarily drawn for the right honing stone 18).

In the clamping position, clamping elements 102 are each arranged on the side of the assigned honing stone 18 opposite the respective joining section 80, when seen in the circumferential direction U. Clamping elements 102 are thus arranged between the two honing stones 18, when seen in the circumferential direction U. Each clamping element 102 abuts with its long base surface 104 on bottom surface 88 of central receiving region 86. Clamping elements 102 are oriented such that second clamping surfaces 110 of clamping elements 102 face each other. Each clamping element 102 with its respective first clamping surface 108 abuts on a respective third side surface 126 of the honing stone 18 assigned to it. A contact surface 128 between honing stone 18 and clamping element 102 extends in axial direction (in FIG. 7 orthogonal to the drawing plane) and in radial direction R.

Fixing element 112 is arranged between clamping elements 102 in the circumferential direction and is oriented such that short base surface 114 faces support 76. Fixing element 112 abuts with its leg surfaces 118 on second clamping surfaces 110 of clamping elements 102. A contact surface 130 between fixing member 112 and the respective clamping member 102 extends in axial direction (in FIG. 7 orthogonal to the drawing plane) and in a further direction 132 which, when looking at a plane orthogonal to the axial direction, is at an angle α relative to the radial direction (R) passing through edge 134 between second clamping surface 110 and long base surface 104 of the respective clamping element 102 (see FIG. 7). Preferably, angle α is about 25° to 35°.

Clamping device 100 further comprises a tensioning mechanism 136 by means of which fixing element 112—for transferring clamping device 100 into the clamping position—can be moved in the radial direction, in particular radially inwards (opposite to the arrow marked “R” in FIGS. 7 and 8). Tensioning mechanism 136 is preferably formed as a screwed connection and comprises a plurality of fastening screws 138 which extend through corresponding threadless radial openings 140 of fixing element 112 and engage in corresponding radial threaded bores 142 of support 76 (see FIGS. 9 and 11).

When fixing screws 138 are tightened, fixing element 112 is moved radially inwards, i.e. towards support 76 (opposite to the arrow marked “R”). Fixing element 112 slides with its leg surfaces 118 along second clamping surfaces 110 of clamping elements 102, which extend parallel to leg surfaces 118. Since contact surfaces 130 between fixing element 112 and clamping elements 102 are inclined relative to the radial direction R, clamping elements 102—when fixing element 112 moves radially inwards—are each strained in the circumferential direction U outwards (in opposite directions). Thereby, clamping elements 102 with their respective first clamping surfaces 108 urge the respective honing stone 18 against the respective joining section 80. In this way, a clamping effect is achieved.

In the clamping position, honing stones 18 are clamped between respective section 80 and respective clamping element 102 assigned to them. The respective clamping element 102 is, in turn, clamped between the respective honing stone 18, bottom surface 88 and fixing element 112. Fixing element 112 is, in turn, held to support 76 in a lost-proof manner by fastening screws 138.

To remove the clamping effect of clamping device 100—e.g. for replacing a worn honing stone—merely fastening screws 138 must be released. A complete dismounting of fixing element 112 from support 76 is preferably not necessary for replacing honing stones 18.

With embodiments not depicted, a kinematic reversion may also be possible in the sense of the invention, in which a movement of fixing element 112 radially outwards (in the direction of the arrow marked “R”) leads to a movement of clamping elements 102 in the circumferential direction towards the respective honing stone 18. For example, it is conceivable that clamping elements 102 and fixing element 112 are arranged mirrored with respect to a plane orthogonal to the radial direction, and a tensioning mechanism 136 comprises one or more pressing screws which engage in corresponding threaded radial holes of the fixing element and bear with an end head on bottom surface 88 of central receiving region 86. In this way, when the pressing screws are tightened, fixing element 112 can be moved radially outwards. 

1. A honing tool (10) comprising a tool body (11) in lightweight construction and at least two radially feedable hone strips (16), wherein the at least two radially feedable hone strips (16) are radially feedable by means of a rack-and-pinion gear (44), wherein the rack-and-pinion gear (44) comprises a central toothed shaft (40) which is adapted and arranged to interact with gear racks (42) associated respectively with the at least two radially feedable hone strips (16) to feed the at least two radially feedable hone strips (16), characterised in that the honing tool (10) comprises a pneumatic measuring device (26) for in-process diameter measurement of a diameter of an opening to be machined in a workpiece.
 2. The honing tool (10) according to claim 1, characterized in that the tool body (11) comprises a functional section (12) and a coupling section (14), wherein the functional section (12) comprises the at least two radially feedable hone strips (16) and the pneumatic measuring device (26), and the coupling section (14) comprises an interface for coupling the honing tool (10) to a honing spindle, and wherein the functional section (12) is gimbal-mounted in relation to the coupling section (14).
 3. The honing tool (10) according to claim 2, characterized in that the coupling section (14) comprises a coupling plate (30) on the spindle side, and two extensions (32) which form a bearing fork (34) for a gimbal bearing of the functional section (12) in relation to the coupling section (14).
 4. The honing tool (10) according to claim 3, characterized in that a first pivoting element (36) is mounted pivotably relative to the two extensions (32) about a first pivoting axis (S1), wherein the first pivoting element (36) is formed by a frame element (36) which is arranged pivotably between the two extensions (32), and a second pivoting element (38) is mounted pivotably relative to the first pivoting element (36) about a second pivoting axis (S2) which is arranged orthogonally to the first pivoting axis (S1), wherein preferably the second pivoting element (38) is formed pin-like and in particular extends through the frame element (36).
 5. The honing tool (10) according to claim 1, characterized in that the functional section (12) comprises two plate-like elements (46, 48) between which the at least two radially feedable hone strips (16), the pneumatic measuring device (26) and the rack-and-pinion gear (44) are arranged.
 6. The honing tool (10) according to claim 5, characterized in that the pneumatic measuring device (26) comprises measuring strips (22) with measuring nozzles (24) arranged thereon, wherein the measuring strips (22) are held in measuring strip holders (20) which extend from the first plate-like element (46) to the second plate-like element (48), and/or in that the at least two radially feedable hone strips (16) extend from the first plate-like element (46) to the second plate-like element (48).
 7. The honing tool (10) according to claim 1, characterized in that the pneumatic measuring device (26) comprises measuring strips (22) with measuring nozzles (24) arranged thereon, wherein for each measuring strip (22) one positioning device (52) is provided which is adapted to adjust the radial position of the respective measuring strip (22).
 8. The honing tool (10) according to claim 7, characterized in that a positioning device (52) is formed by a screw-based fastening of the measuring strips (22) with respect to the functional section (12), wherein the fastening of the measuring strips (22) comprises at least a first screw (54) which is screwed into the functional section (12) and holds a measuring strip (22) or a corresponding measuring strip holder (20) from radially outwards, and a second screw (56) which is screwed into the measuring strip (22) or the corresponding measuring strip holder (20) and abuts on the functional section (12) such that the measuring strip (22) can be moved radially outwards relative to the functional section (12) by screwing the second screw (56) into the measuring strip (22) or the corresponding measuring strip holder (20).
 9. A hone strip (16) for use in the honing tool (10) according to claim 1, the hone strip (16) comprises a support (76) and at least one honing stone (18), characterized in that the support (76) has a clamping device (100) by means of which the at least one honing stone (18) can be releasably clamped and fixed to the support (76) in a clamping position of the clamping device (100).
 10. The hone strip (16) according to claim 9, characterized in that the clamping device (100) has at least one joining section (80), in particular fixedly arranged on the support (76), and a clamping element (102), wherein the at least one joining section (80) is adapted and arranged such that in the clamping position the at least one honing stone (18) abuts on the at least one joining section (80) in a circumferential direction (U), and wherein the clamping element (102) in the clamping position is arranged in the circumferential direction (U) on the opposite side of the at least one honing stone (18), abuts on and urges the at least one honing stone (18) in the circumferential direction (U) against the at least one joining section (80), so that the at least one honing stone (18) is clamped and held between the at least one joining section (80) and the clamping element (102).
 11. The hone strip (16) according to claim 10, characterized in that the clamping device (100) comprises a fixing element (112) which is adapted and arranged such that, in the clamping position, the fixing element (112) abuts on and urges the clamping element (102) towards the at least one joining section (80).
 12. The hone strip (16) according to claim 10, characterized in that a contact surface (124) between the at least one joining section (80) and the at least one honing stone (18) lies in a plane which extends substantially in the axial and radial directions, and/or in that a contact surface (128) between the clamping element (102) and the at least one honing stone (18) lies in a corresponding plane which extends substantially in the axial and radial directions.
 13. The hone strip (16) according to claim 11, characterized in that a contact surface (130) between the fixing element (112) and the clamping element (102) lies in a plane which extends in the axial direction and extends in a further direction (132) which is at an angle (a) relative to the radial direction (R), when looking at a corresponding plane extending orthogonally to the axial direction, wherein this angle (α) is either between 15° and 45°, or between 20° and 40°, or between 25° and 35°.
 14. The hone strip (16) according to claim 11, characterized in that the clamping element (102) and the fixing element (112) are adapted and arranged such that the fixing element (112) urges the clamping element (102) in a circumferential direction (U) towards the at least one honing stone (18) when the fixing element (112) moves in the radial direction (R), in particular radially inwards.
 15. The hone strip (16) according to claim 11, characterized in that the clamping device (100) comprises a tensioning mechanism (136) which is adapted to move the fixing element (112) during the transfer into the clamping position in the radial direction (R), in particular radially inwards.
 16. The hone strip (16) according to claim 9, characterized in that the hone strip (16) has two honing stones (18), the clamping device (100) has two joining sections (80) arranged outside in a circumferential direction (U), two clamping elements (102) arranged between the two honing stones (18) when viewed in the circumferential direction (U), and at least one fixing element (112) arranged between the clamping elements (102) when viewed in the circumferential direction (U).
 17. The honing tool (10) according to claim 1, characterized in that the honing tool (10) comprises at least one hone strip (16) having a support (76) and at least one honing stone (18), the support (76) having a clamping device (100) by means of which the at least one honing stone (18) can be releasably clamped and fixed to the support (76) in a clamping position of the clamping device (100).
 18. The honing tool (10) according to claim 2, characterized in that the functional section (12) comprises two plate-like elements (46, 48) between which the at least two radially feedable hone strips (16), the pneumatic measuring device (26) and the rack-and-pinion gear (44) are arranged.
 19. The honing tool (10) according to claim 2, characterized in that the pneumatic measuring device (26) comprises measuring strips (22) with measuring nozzles (24) arranged thereon, wherein for each measuring strip (22) one positioning device (52) is provided which is adapted to adjust the radial position of the respective measuring strip (22).
 20. A hone strip (16) for use in the honing tool (10) according to claim 2, the hone strip (16) comprises a support (76) and at least one honing stone (18), characterized in that the support (76) has a clamping device (100) by means of which the at least one honing stone (18) can be releasably clamped and fixed to the support (76) in a clamping position of the clamping device (100) 